Bluetooth surveillance secretly tested in the city of Bath

“In 2001 Jose Emilio Suarez Trashorras was jailed in a Spanish prison for drug related offences. Whilst imprisoned, Trashorras established regular contact with Jamal Ahmidan who was serving time for a petty crime. Both individuals embraced radical Islamic fundamentalist ideas within the prison and were recruited in the Takfir wa al-Hijra group, a Moroccan terrorist groups linked with al-Qaida . Following their release, Ahmidan became the leader of the terrorist cell that conducted the Madrid bombing. In a drugs-for-bombs exchange with a third party, Trashorras provided the explosives for the 13 backpack bombs that killed 191 people and injured hundreds.“

So write Vassilis and Panos Kostakos in the department of computer science and the University of Bath in the UK, who have come up with a system that they say could spot and monitor these kinds of interactions in prisons.

Their idea? Fit inmates with RFID tags that allow their positions to be monitored, and then number crunch the resulting data sets to see who spends the most time with whom.

Not exactly rocket science but the Kostakos’s have an even more frightening idea. Why not test the idea by anonymously monitoring the movements of students, residents and workers of the city of Bath by listening out for their bluetooth-enabled devices as they move around the city. And that’s what they’ve done.

What the Kostakos found is that it is straightforward to capture data on people’s encounters using bluetooth. In fact they captured data on 10,000 unique devices during the 6 month study. Yep, that’s 10,000.

Exactly how much you can tell about these encounters isn’t clear. But hey, this is only a demonstration (either that or they’re keeping schtum about the juicy details).

Of course, it’s already possible to make inferences about encounters between individuals using the location information from cellphone networks. But that isn’t easily accessible to ordinary folk and in any case has a blunt resolution of a mile or so. Bluetooth, on the other hand, gives your location to within 10 metres or so.

The moral? Turn off your bluetooth enabled devices when in the city of Bath (and anywhere else). In other hands, this kind of data could be dangerous.